Apparatus for making spunbond from continuous filaments

Patent metadata

Field	Value
Publication number	US-11225739-B2
Application number	US-201815939703-A
Country	US
Kind code	B2
Filing date	Mar 29, 2018
Priority date	Mar 31, 2017
Publication date	Jan 18, 2022
Grant date	Jan 18, 2022

Abstract

An apparatus for making a nonwoven spunbond web has a spinneret for making endless filaments moving in a predetermined direction. A monomer extractor downstream from the spinneret has an upstream extractor end face directed upstream and forming a gap with a downstream spinneret end face. A cooler downstream of the extractor for the filaments has an upstream cooler end face forming with a downstream extractor end face a second gap. A stretcher downstream of the cooler for the cooled filaments has an upstream stretcher end face forming a third gap with the downstream cooler end face. The filaments are deposited on a web former by the stretcher to form the nonwoven spunbond web. A deformable seal for seals one of the gaps, and means connected to the deformable seal press the seal against the end faces forming the one gap with a variable pressure or contact face.

First claim

We claim:

1. An apparatus for making a nonwoven spunbond web from filaments that are thermoplastic and continuous, the apparatus comprising:
a spinneret for spinning the filaments in a predetermined direction and having a downstream spinneret end face directed downstream in the predetermined direction;
a monomer extractor downstream in the predetermined direction from the spinneret and having an upstream extractor end face directed upstream and forming a first gap with the downstream spinneret end face, the monomer extractor having an opposite downstream extractor end face directed downstream;
a cooler downstream of the extractor for cooling the filaments and having an upstream cooler end face forming with the downstream extractor end face a second gap and an opposite downstream cooler end face;
a stretcher downstream of the cooler for stretching the cooled filaments and having an upstream stretcher end face forming a third gap with the downstream cooler end face, the extractor, the cooler, and the stretcher forming a continuous passage extending in the predetermined direction;
a web former on which the filaments are deposited by the stretcher to form the nonwoven spunbond web;
a deformable hollow seal in the second gap, fillable with a fluid medium for sealing between the respective end faces, fixed to the monomer extractor, and having a principal direction of deformation extending in the predetermined direction toward the cooler;
another deformable hollow seal in the third gap, fillable with a fluid medium for sealing between the respective end faces, fixed to the stretcher, and having a principal direction of deformation extending in the predetermined direction toward the cooler; and
means connected to the deformable seals for introducing the fluid medium into the seals or removing the fluid medium from the seals for pressing the seals against the respective end faces forming the respective gaps with a variable pressure or contact force and thereby varying a dimension of the seals in the predetermined direction to compensate for non-uniformities of a dimension of the respective gaps between the respective end faces in the predetermined direction and maintain the seals in contact with both of the respective end faces.

2. The apparatus defined in claim 1 , wherein there are three such seals, one being provided in each of the gaps, each of the seals being connected to the means.

3. The apparatus defined in claim 1 , wherein the dimension in the predetermined direction of the first gap between the spinneret and the monomer extractor or the width of the second gap between the monomer extractor and the cooler or the width of the third gap between the cooler and the stretcher when the apparatus is operating is 3 to 35 mm and the respective seal seals across this dimension.

4. The apparatus defined in claim 3 , wherein the dimensions in the predetermined direction of the seals is adjustable in the predetermined direction in the gap by 3 to 20 mm.

5. The apparatus defined in claim 1 , wherein the seals extend s annularly around the passage.

6. The apparatus defined in claim 1 , wherein a plurality of the seals are arranged adjacent to one another in the one gap.

7. The apparatus defined in claim 1 , wherein the means for pressing can press the seal against the end faces of the respective gap with a pressure of more than 2000 Pa.

8. The apparatus defined in claim 1 , wherein the seals are inflatable.

9. The apparatus defined in claim 1 , further comprising:
means usable during maintenance of the apparatus for shortening the seals in the predetermined direction and thereby permitting relative movement in a direction transverse to the predetermined direction of the end faces defining the one gap.

10. The apparatus defined in claim 9 , wherein shortening of the seal moves the seals out of contact with one of the respective end faces forming the respective gap.

11. The apparatus defined in claim 1 , wherein the cooler and the stretcher form a subassembly closed to entry of air from outside the passage.

12. The apparatus defined in claim 1 , further comprising:
a diffuser between the stretcher and the web former, forming part of the passage, receiving the filaments from the stretcher, and having secondary air inlet gaps through which secondary air passes into the diffusor.

13. The apparatus defined in claim 12 , wherein the web former includes a foraminous belt on which the filaments are deposited by the diffuser, the apparatus further comprising:
extractor means juxtaposed with the web former for drawing tertiary air in the predetermined direction through the belt and along outer surfaces of the diffusor so as to mix with primary air flowing in the predetermined direction through the passage.

14. The apparatus defined in claim 13 , wherein the belt and a region of the belt underneath the diffuser has a width at least 20% greater than a width of the diffuser at a downstream end of the diffuser walls.

15. The apparatus defined in claim 12 , wherein a ratio of volume flows of the primary and secondary air is less than 5:1.

16. The apparatus defined in claim 12 , wherein walls of the diffuser converge downstream of the secondary air inlet gaps.

17. The apparatus defined in claim 16 , wherein after converging at a constriction downstream in the predetermined direction from the secondary air inlet gaps, the walls of the diffuser diverge.

18. The apparatus defined in claim 12 , wherein the secondary air inlet gaps open into the diffuser at an angle of less than 100° to the predetermined direction.

Assignees

• Reifenhaeuser Masch
• Reifenhaeuser Gmbh & Co Kg

Inventors

• Frey Detlef
• Neuenhofer Martin
• Sommer Sebastian

Classifications

• D01D13/02

  Elements of machines in combination · CPC title

• D04H17/00 Primary

  Felting apparatus · CPC title

• D01D5/092 Primary

  in shafts or chimneys · CPC title

• D04H3/00 Primary

  Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length · CPC title

• D04H3/16 Primary

  with bonds between thermoplastic filaments produced in association with filament formation, e.g. immediately following extrusion · CPC title